code: def _scalar(order):
      """Compute the scalar used in the recursive expression.
  
      Args:
          order (int): order of Trotter product (assume order is an even integer > 2).
  
      Returns:
          float: scalar to be used in the recursive expression.
      """
      root = 1 / (order - 1)
      return (4 - 4**root) ** -1
  
file_path: pennylane/pennylane/templates/subroutines/trotter.py
imports: import pennylane
  from pennylane.operation import Operation
  from pennylane.ops import Sum
label_desc: Use image node_id 1 for calling a global function with example usage: _scalar(order) and returns: unknown